Lego (for its normal, children focused sets) is packaged quite compactly and it never made a difference to my kids, b/c they knew whatever was in the box was going to be larger when it was assembled. I also never opened a Lego box and found damage like I have with PM due to loose parts knocking against each other, something which has been noted frequently on this forum.
Comparing LEGO to playmobil is problematic
LEGO enjoys a vast cult following and has no problem with brand recognition. Ask any stranger on the street what LEGO is . Then ask what playmobil is.
When I do shows in the US very few people are aware what playmobil even is. The people who are not even familiar with toy brands just automatically assume it’s LEGO. They obviously don’t even know what LEGO looks like but they sure are familiar with the brand name.
So as a marketers stand point playmobil needs to command more of a product shelf appearance